Lightweight fan

ABSTRACT

A lightweight automotive fan having a plastic core and high strength metal sheets applied to the front and rear faces of the core.

United States Patent [191 3,825,369 Albertzart July 23, 1974 [5 LIGHTWEIGHT FAN 2,775,426 12/1956 Barrett et al 416/241 x 3,132,841 5/1964 Wilder... [75] Inventor: R. RIch3l'd Albertzart, Okemos, 3,572,971 3/1971 Seiwen Mlch- 3,628,888 12/1971 Wooden...

Assigneez ay i c rp i Jackson, Morley X FOREIGN PATENTS OR APPLICATIONS [22] Filed: Sept. 13, 1972 12,846 1909 Great Britain 416/240 [21] Appl NO. 288 762 152,416 10/1920 Great Britain 416/210 U S Cl 416/229 6/210 416/241 Primary Examiner-Everette A. Powell, Jr.

[51] Int. Cl F04d 29/38 [58] Field of Search 416/229, 230, 241 A, 224, [57] ABSTRACT 416/210 A lightweight automotive fan having a plastic core and [56] References Cited high strength metal sheets applied to the front and UNITED sTATEs PATENTS rear faces of the core 1,248,151 11/1917 Mott 416/224 3 Claims, 3 Drawing Figures LIGHTWEIGHT FAN BACKGROUND OF THE INVENTION This invention is related to automotive fans and in particular to a lightweight fan.

Automotive fans are subjected to extremely high stresses and must be fairly large to pump a sufficient amount of air in most applications. To fulfill the necessary requirements for an automotive fan, most of the prior fans have been constructed from metal. For this reason, automotive fans are quite heavy and require a considerable amount of power to operate. Moreover, the weight of the fan applies stresses to other components of the vehicle.

All plastic automotive fans have been utilized in the past. These fans have not been sufficiently strong for use in high stress applications.

SUMMARY OF THE INVENTION This invention responds to the problems of the prior art by presenting a fan which is not only light in weight but also is strong enough to be used in high stress applications. In a preferred embodiment, the hub and spider arms of the fan are formed from a plastic material. The front and rear faces of the hub and spider arms are covered with high strength thin sheets of metal which also may be used to form the fan blades.

In a preferred embodiment of the invention the metal facings are formed from a single piece of high strength stainless steel. The metal facings may be bonded to the plastic by a resin such as an epoxy resin.

BRIEF DESCRIPTION OF THE DRAWINGS The features of this invention will become more apparent in the following detailed description of a preferred embodiment when read in conjunction with the Figures in which:

FIG. 1 is a rear view of a portion of a fan embodying the principles of this invention.

FIG. 2 is a bottom view of the portion of the fan depicted in FIG. 1, taken along line 2--2.

FIG. 3 is an end view of the fan depicted in FIG. 1, taken along line 3-3.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the Figures, wherein like reference numerals indicate like parts, a fan is denoted generally by the reference numeral 10. The fan includes a hub portion 12 which includes mounting holes 14. A plurality of spider arms 16 emanate radially from the hub 12. The spider arms 16 may be asymmetrically spaced if it is desired. The spider arms 16 link the hub 12 and the fan blade 18.

As is most clearly shown in FIGS. 2 and 3 the fan 10 includes a central non-metallic core 20 which is preferably a plastic material and thin metal members 22, 24 on the front and rear faces of the plastic core 20. The

2 plastic core 20 includes a central portion in the shape of the hub 12 and a plurality of rectangular arms 16 which emanate radially from the hub 12. The arms 16 are twisted with respect to the plane of the hub 12. The metal facing members 22, 24 include a hub shaped portion, an arm shaped portion and a portion which defines the fan blade 18.

The facing members 22, 24 are substantially coextensive with the plastic member 20 and may be tightly bonded thereto by the use of an epoxy resin or the like. The portions of the metal facings 22, 24which define the blades 18 may be bonded at the leading edge 26 and the trailing edge 28 by processes well known in the art such as soldering and brazing among others.

The plastic core 20 by virtue of its thickness gives the fan 10 the requisite stiffness. Themetal facing members 22, 24 by virtue of their high tensile strength give the composite fan the necessary strength. In a preferred embodiment of this invention the plastic member 20 was made from polypropylene and the facing members 22, 24 were made from a high strength stainless steel. The combined strength of the facing material and stiffness of the core provides a rugged fan which is still of quite light weight.

Although it is preferred to construct the facing materials from a single sheet, they may be made of separate pieces. Furthermore, in some applications the spider arm 16 may be shorter than that illustrated in the preferred embodiment such that the end of the blade may be joined along with the leading and trailing edges.

What is claimed is:

1. A lightweight automotive fan comprising:

a one-piece plastic core member defining a central hub portion and a plurality of arms extending radially from said hub for stiffening the blade portions of said fan; and

thin metal facing sheet members bonded to the front and rear portions of said core member;

said facing sheet members substantially covering said faces of said core member and defining a hub portion, a relatively narrow intermediate arm portion, and a relatively wide fan blade portion of greater dimension than said arm portion of said core member sandwiched between said fan blade portions of said facing sheet members;

said fan blade portions of said facing sheet members being joined to each other at their respective leading and trailing edges and being curved rearwardly to form a radially untwisted, airfoil shaped fan blade.

2. The automotive fan set forth in claim 1 wherein said plastic is polypropylene and said metal facing members are stainless steel.

3. The automotive fan set forth in claim 1 wherein said facing members are substantially identically shaped.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,825,369 Dated July 23, 1974 Inventor s R. Richard Albertzart It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Colum 2, line 55, change claim "1" to read claim 2--.

Signed and Sealed this sixteenth D21) 0f September 1975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner oj'Paienis and Trademarks 

1. A lightweight automotive fan comprising: a one-piece plastic core member defining a central hub portion and a plurality of arms extending radially from said hub for stiffening the blade portions of said fan; and thin metal facing sheet members bonded to the front and rear portions of said core member; said facing sheet members substantially covering said faces of said core member and defining a hub portion, a relatively narrow intermediate arm portion, and a relatively wide fan blade portion of greater dimension than said arm portion of said core member sandwiched between said fan blade portions of said facing sheet members; said fan blade portions of said facing sheet members being joined to each other at their respective leading and trailing edges and being curved rearwardly to form a radially untwisted, airfoil shaped fan blade.
 2. The automotive fan set forth in claim 1 wherein said plastic is polypropylene and said metal facing members are stainless steel.
 3. The automotive fan set forth in claim 1 wherein said facing members are substantially identically shaped. 